[LAD] zretune app added to libzita-resampler

[Nils Gey]

On Tue, 25 Sep 2012 11:43:36 +0000
Fons Adriaensen <fons at linuxaudio.org> wrote:

> Hello all,
> 
> Release 1.2.0 of libzita-resampler now include the 'zretune'
> For example 
> 
>   zretune --cent 50 input.wav output.wav
> 
> will result in a file that sounds a quarter tone higher
> and is about 1.5 percent shorter.


Can it do the reverse?  The analysis of the current frequency is the hard part, not the speeding up and down, which can be done with sox already:
sox 440Hz.wav 432Hz.wav pitch -31

For example, to tune a file to 440hz: 
zretune 440 input.wav output.wav   

or even more convenient, when dealing with equal temperament:

zretune 60 in.wav out.wav

to tune to the frequency of midi key 60, which is the middle C.


Nils